000 AXPZ20 KNHC 031603 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1501 UTC Tue Apr 3 2018 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough reaches from 07N80W to 03.5N100W. The intertropical convergence zone reaches from 03.5N100W to beyond 06N140W. Scattered moderate convection is noted within 90 nm either side of the ITCZ between 117W and 132W, and within 150 nm north of the ITCZ west of 135W. Farther south, a second intertropical convergence zone extends from 03.4S92W to 02SN97W to 03.4S108W. No significant convection is noted. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends SE across the offshore forecast waters through the Revillagigedo Islands maintaining mainly gentle to moderate NW-N winds, and seas of 4 to 6 ft in open waters. Little change in these marine conditions is expected into Thu. An upper distubance will shift eastward across the region late Thu, allowing moderate to locally fresh NW-N winds and seas in the 5-8 ft range mainly in the waters N of Cabo San Lazaro as the pressure gradient slightly tightens. Farther south in the Gulf of Tehuantepec, a weak pressure pattern supporting generally light winds will transition through mid week as high pressure builds north of the region. This willl support fresh to strong gap winds through the Gulf of Tehuantepec Wed night into Thu. Currently, marine guidance suggests northerly winds of 20-30 kt and seas in the 6-9 ft range with this event. Climatologically speaking, the final gale force gap wind event occurs in the Gulf of Tehuantepec in late March or early April. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: moderate to fresh NE-E winds are expected on Thu, with seas generally in the 4-7 ft range. Gentle to moderate winds will prevail the remainder of the forecast period. Gulf of Panama: gentle to moderate N-NE winds will prevail through Wed, with seas of 4-7 ft in long period SW swell. Light and variable winds are expected thereafter. Elsewhere, light and gentle winds are generally expected, with a better defined southerly wind flow S of 07N/08N by Thu. Seas of 5-7 ft in long period SW swell will subside to 3-5 ft Wed through Fri. REMAINDER OF THE AREA... A broad ridge dominates the forecast region north of 15N and W of 110W related to 1021 mb high pressure located well N of the area near 38N129W. A new high pressure center is forecast to develop along the ridge axis over the northern forecast waters near 28N125W, and it will remain nearly stationary over the next 48 to 72 hours. The pressure gradient between the ridge and lower pressures in the vicinity of the ITCZ will result in moderate to locally fresh trade winds and seas to near 8 ft, particularly across the waters from 08N to 15N W of 125W through late in week. A new cold front approaching from the west will bring an increase in winds and seas across the far NW waters on Wed. Expect fresh to strong southerly winds and seas of 8-9 ft ahead of the front and NW of a line from 30N136W to 27N140W by late Wed. Winds will increase again acros the NW corner of the forecast region Thu night into Fri in association with a strong low pressure system crossing N of the area. $$ Christensen